Answer:
m∠ABD = 114°
Step-by-step explanation:
Given measurements of interior angles are:
m∠D = 2n°
m∠C = 60°
m∠ABD = (4n+6)°
The measurement of exterior angle of a triangle is equal to the sum of two opposite interior angles.
This can be mathematically expressed as:
m∠ABD = m∠C+m∠D
Putting the respective values
[tex]4n+6 = 2n+60\\4n-2n+6 = 60\\2n+6 = 60\\2n = 60-6\\2n = 54\\\frac{2n}{2} = \frac{54}{2}\\n = 27[/tex]
Putting n=27 in (4n+6)°
[tex]=4(27) + 6\\= 108+6 = 114[/tex]
Hence,
m∠ABD = 114°
